Improvement in mqlders  draw-spikes



UNITED STATES PATENT OFFICE.

ROBERT A. THOMPSON, OF BEAVER FALLS, PENNSYLVANIA.

IMPROVEMENT IN MQLDERS DRAW-SPIKES.

Specification forming part of Letters Patent No. 137,637, dated April 8,1873; application filed August 31, 1872.

To all whom it may concern:

Be it known that I, ROBERT A. THOMPSON, of Beaver Falls, in the countyof Beaver and State of Pennsylvania, have invented certain new anduseful Improvements in Molders Draw Spikes or Hooks; and I do herebydeclare that the following is a full, clear, and exact descriptionthereof, that will enable others skilled in the art to which itappertains to make and use the same, reference being had to theaccompanying drawing and to the letters of reference marked thereonwhich form a part of this specification.

My invention relates to an improvement in the construction of the drawspikes or hooks used by molders to draw the patterns of stoveplates andother light or thin and ornamental castings from the sand.

These spikes or hooks are usually made from metal rods, with one endpointed and provided with a hook or with a screw or gimlet point, theother end being bent into a rigid ring or eye. This ring end of thedraw-spike is used as a hammer for tapping the pattern, in order todisengage it from the sand of the mold previous to its being withdrawntherefrom. With thin or light castings, such as stove-plates, which haveornamental designs, delicate tracery, and fine lettering to be cast inrelief, this tapping of the patterns to disengage them from the adheringsand of the mold is a very delicate operation, as the percussionresulting from the blow of a rigid hammer on the pattern tends todisintegrate the sand and break the mold in withdrawing the pattern,thereby necessitating a careful after manipulation by the hand or trowelin order to restore the broken portions of the mold, or, as isfrequently the case, necessitat= ing an entirely new impression of thepattern.

My invention is designed to obviate this difficulty 5 and it consists inmaking the head or eye of the draw-spike in the form of a spring insteadof rigid, as heretofore, so that when used as a hammer for tapping thepatterns the concussion or force of the blow will be borne by thespring-ring or hammer end of the drawspike, and the mold be therebyrelieved from its disintegrating effect on the sand.

In the accompanying drawing, Figure 1 is a side elevation of my improveddraw-spike. Fig. 2 is a plan view of the same, showing the hooked point.

A represents the body of the spike; B, the end provided with thedrawing-hook O, the end formed with the sprin g ring or eye to be usedas a tappinghammer.

This spring may be made of steel or any metal pr material havingsufficient strength and elasticity for the required purpose, and it mayalso be made of any shape, as found most convenient. 1

To those skilled in the art further description of the operation ofmyinvention is deemed unnecessary.

What I claim as my invention is- A molders draw-spike having aspring-hammer head, substantially as described, and for the purposespecified.

In testimony that I claim the foregoing I have hereunto set my hand this29th day of August, 1872.

R. A. THOMPSON.

Witnesses:

J. W. Fonnns, J. G. HARBISON.

